[pHaTtYaSs2x4]

I'm still working on my project and am wondering..... Will going with a D4 benifit me at all? TDX block w/#4 nozzle, 2-342(single pass)hc and 1250 pump.
I'm only going to be watercooling my CPU, no future plans for NB or GPU.
Also, anyone know how to prevent water being sucked into the loop on a 5 1/4 bayrez? It's driving me nuts!